Effects of Y doping ions on microstructure, dielectric response, and electrical properties of Ca1−3x/2Y x Cu3Ti4O12 ceramics

Abstract

The effects of Y 3? doping ions on ceramic microstructure, dielectric response, and electrical properties of Ca 1-3x/2 Y x Cu 3 Ti 4 O 12 (x = 0, 0.05, 0.10, and 0.15) ceramics prepared by a modified sol-gel method were investigated. A grain size of Ca 1-3x/2 Y x Cu 3 Ti 4 O 12 was reduced by Y 3? ions due to a solute drag effect. Substitution of CaCu 3 Ti 4 O 12 ceramics with suitable Y 3? concentration of 5 at. % can improve dielectric properties with high-dielectric permittivity of e 0 * 1.37 9 10 4 and low tand * 0.05 at 1 kHz. The results revealed that the relationship of the mean grain size and e 0 cannot be formulated. Using impedance spectroscopy analysis, the grain boundary resistance (R gb ) of Ca 1-3x/2 Y x Cu 3 Ti 4 O 12 ceramics was found to be strongly enhanced by Y 3? doping ions with x = 0.05. With further increasing x from 0.05 to 0.15, R gb decreased. While the grain resistance tended to increase with increasing Y 3?concentration (x = 0-0.15). Variation of a low-frequency tand value in all Ca 1-3x/2 Y x Cu 3 Ti 4 O 12 ceramics due to the influence of Y 3? substitution was well consistent with their changes in R gb values. Non-Ohmic properties of Ca 1-3x/2 Y x Cu 3 Ti 4 O 12 ceramics were also investigated.

Grain boundary engineering that induces ultrahigh permittivity and decreased dielectric loss in CdCu3Ti4O12 ceramics

“…Indeed, the radii of the semicircles decrease with increasing temperature, confirming that the resistivity of the grain boundaries is inversely proportional to temperature, which is a typical behavior of degenerate semiconductors. According to the temperature dependence of the resistivity, the activation energy E gb can be calculated by the Arrhenius law:where σ 0 is the pre‐exponential temperature‐dependent constant, k B is the Boltzmann constant, and T is the absolute temperature. A linear fitting of ln σ gb vs 1000/ T provides E gb , as displayed in the inset.…”

Research progress on quadruple perovskite oxides

“…Numerous strategies have been investigated, such as streamlining the preparation procedure, [200][201][202] switching metal ions, 203,204 adding a second phase [205][206][207][208][209] and lowering the grain size. [210][211][212] The dopingmodification approach is one of these strategies that has been shown to be important and successful. 213,214 Through meticulous selection and integration of suitable doping elements in the CCTO lattice, it is possible to augment the dielectric characteristics of CCTO materials, hence augmenting their dependability and stability in real-world scenarios.…”